Sewing machine



M. McCANN SEWING MACHINE Jan. 15, 1935.

Original Filed July 26, 19 30 2 Sheets-Sheet 1 a g x 2 9 flhi" a M. MCANN SEWING MACHINE Jan. 15, 1935.

Original Filed July 26, 1930 2 Sheets-Sheet 2 22m? Wzkfiaeifilama w MWJPatented Jan. 15, 1935 PATENT OFFICE SEWING MACHINE Michael McCann, St.Albans, N. Y., assignor, by

mesne assignments, to The Singer Manufacturing Company,'Elizabethport,N. J., a corporation of New Jersey Original application July 26, 1930,Serial No.- 470,861. Divided and this application February 6, 1932,SerialNo. 591,253

Claims. (01. 112453 This invention'relates to sewing machines and hasfor its object to'provide means for engaging the starting end of aneedle thread, more particularly in achain stitch or single threadmachine,

to prevent 'it from being drawn back through the needle eye to unthreadthe needle at the start of the sewing operation.

The present application in part covers subject matter divided out frommy application Serial No. 470,861, filed July 26, 1930 for sewingmachines.

Referring to the accompanying drawing Figure 1 is a side elevationpartly broken away of a single thread sewing machine of the buttonsewing type and embodying the invention, the machine shown beingparticularly intended for wrapping wires or other strands with thread,the machine forming loops of thread which are passed about the wiresalternately in opposite directions, successive loops being engaged inchain stitch formation,

Figure 2 is a front end elevation of the machine "showing the workholder depressed.

Figure 3 is a view similar to a portion'of Figure 2, but showing thework holder elevated.

Figure 4 is a horizontal section on line 4-4 of Figure 1.

Figures 5, 6 and '7 are views similar to Figures 2,3, and 4,respectively ,-but illustrating a modi- Figure 8 is a fragmentaryperspective of the thread end gripping device of Figures 5, 6 and 7.

Figure 9 is a section on line 9--9 of Figure 8.

Referring to Figures 1 to 4 inclusive, at 1 is shown the base of asewing machine of a well known type for securing buttons with a singlethread chain stitch, having a post 2 upstanding from its rear endmerging with a forwardly extending arm 3 having a sewing head 4 at itsforward end. At 5 is indicated a needle bar to the lower end of which aneedle 6 having an eye"? is secured.

In the machine shown suitable means not material to this invention areemployed to vibrate the needle laterally between its sewing strokes,though the invention is not limited to a machine having a laterallyvibrating needle.

Beneath the needle bar the base 1 is provided with a work table beneathwhich is positioned a looper such as 26 carried by a looper shaft 27.The looper is driven in suitable timed relation to the shaft 10 by anysuitable means as is well known in the art. Beneath the arm 2 ispositioned a work holder 30 which may be of any desired type, dependingon the work which the machine is to do. As shown it is intendedtoreceive and carry one or more strands of wire about which it isdesired to wrap the loops of thread. Whatever its form it is carried by"a carrier bar 33 hinged on a horizontal pintle 47-at its rear end sothat it may be raised from the work table 25, which when done at the endof the sewing operation causes the thread to be broken, freeing the workfrom the machine. This rais-' ing is effected as shown by rocking arock'shaft' '70 having an arm 71 connected to the work holder 30 as by achain72. The rocking of the shaft '70 against the action of a torsionspring '73 may be effected by any suitable means such as a treadle (notshown) which may be connected thereto through a link 74 connected toan'arm '75 fixed to the shaft '70 at any convenient point.

The machine may be provided with suitable take-up and tension deviceswhich are not material to the subject matter covered by thisapplication.

In accordance with the present invention means'are provided to grasp thestarting end of the thread and hold it until after the stitchingoperation has been well initiated since where the threads are wrappedabout material, as in the present machine, there is little frictionalengagement of the starting end to prevent it from being drawnba'c kthrough the needle eye which would unthread the needle and preventstitching. In order to hold the thread end to prevent it-from payingback through the needle eye at the start of the machine operation it maybe grasped by a tension device shown at 130 in Figures 1 to 4 inclusive.As shown this comprises a resilient hook member in which the thread endmay be caught carried at the lower end of a lever 131, the upper end ofwhich is fixed to the rock shaft 70. The parts are so positioned thatwhen the work holder is allowed to descend toward sewing position on thework table, the hook 130 is caused to move across the needle path fromthe position shown in Figure 3 to that shown in Figure 2, engaging thethread end 135 and drawing it laterally away from the needle path intothe position shown in Figure 2, this thread end being drawn into thebend of the hook 130 and there held with sufficient firmness so that itis not drawn back through the needle eye during the first stitch but isheld for a suflicient time to insure correct formation of the firststitch. It then slips out from the tension device 130 and the stitchingproceeds in the usual manner.

In Figures 5 to 9 inclusive a modification of thread end holding deviceis illustrated, this comprising a spring finger 140 fixed to the lever131 in place of the hook 130 shown in Figures 1 to 4. This spring 140 isfixed remote from the end of the lever as at 141 and adjacent to itsfree end it is preferably provided with a perforation 142 through whichmay extend a'hook 143 with a rounded back face presented toward the freeend of the spring 140 projecting from the lever. The thread may beslipped in over the convex back face of the hook, which is presentedtoward the free ends of the parts 140 and 131, and into engagement withthe oppositely presented concave face of the hook in the normal graspedposition of the thread. The hook and spring act together to retain thethread end portion from too easily slipping out from between the leverand the spring. An adjusting screw 144 determines the pressure withwhich the spring 140 normally engages the face of the lever 131. Withthis arrangement the thread is engaged by the holding device on theswinging of the lever 131 produced when the work holder is raised asshown in Figure 6, and the thread is retained thereby on the motion ofthe work holder when the work holder is returned to operative condition.As the lever 131 is moved to take the thread while the thread is stillheld by both the needle and the work, the engagement of the thread bythe retainer is insured, in this respect this construction beingpreferable to that shown in Figures 1 to 4 in which the thread engagingdevice moves to engage the thread after the thread has become detachedfrom the work.

From the foregoing description of certain embodiments of this inventionit should be evident to those skilled in the art that various changesand modifications might be made without departing from the spirit orscope of this invention as defined by the appended claims.

I claim:

1. In a sewing machine, sewing instrumentalities including a needlehaving an eye, a work table, a work holder liftable from said table atthe endof a stitching operation, means including I a rock shaft forlifting said holder, a lever carried by said rock shaft and having aportion movable across the normal thread path extending fromsaid needleeye toward the work as said holder is lifted and lowered, and means atsaid portion for grasping said thread during one of its movements acrosssaid path and holding the thread end at the start of a succeedingstitching operation.

2. In a sewing machine, sewing instrumentalities including a needlehaving an eye, a work table, a work holder liftable from said table atthe end of a stitching operation, means including a rock shaft forlifting said holder, a lever carried by said rock shaft and having aportion movable across the normal thread path extending from said needleeye toward the work as said holder is lifted and lowered, and a springelement cooperating with said portion for grasping said thread duringone of its movements across said path and holding the thread end at thestart of a succeeding stitching operation.

3. In a sewing machine, sewing instrumentalities including a needlehaving an eye, a work table, a work holder liftable from said table atthe, end of a stitching operation, means including a rock shaft forlifting said holder, a lever carried by said rock shaft and having aportion movable across the normal thread path extending from said needleeye toward the work as said holder is lifted and lowered, and a springfinger secured to said portion and lying therealong and between whichand said portion the thread is passed on lifting movement of saidholder, said portion having a hook extending through a slot in saidfinger for retaining saidthread when said holder is lowered, said fingerand portion acting to hold the starting end of the thread until afterthe start of a subsequent stitching operation.

4. A thread-grasping member comprising parts including a bar and aspring finger secured to said bar and lying therealong and between whichand said bar the thread may be grasped, and a hook element carried bysaid bar and extending into an opening through said finger andpresenting a convex portion over which the thread may pass and a concaveportion for engagement with the thread in its normal grasped position.

5. A thread grasping member comprising a pair of parts yieldinglysecured together and presenting a pairs of free ends between which athread to be grasped may be passed, one of said parts having a hookprovided with a rounded back face presented toward said free ends and aconcave face oppositely presented and the other of said parts having anopening into which said hook normally extends.

MICHAEL McCANN.

